Is there a link between talcum powder, oxidative stress, and ovarian cancer risk?

INTRODUCTION: The link between talcum powder use and cancer, particularly ovarian cancer, has been a topic of scientific research and legal debate for several years. Studies have suggested a potential association between long-term talcum powder use in the genital area and an increased risk of ovarian cancer. AREAS COVERED: The following report includes up-to-date evidence to support the potential link between talcum powder use and the risk of developing ovarian cancer. The International Agency for Research on Cancer, which is part of the World Health Organization, classified talc-based body powder as possibly carcinogenic to humans when used in the female genital area. However, other studies have not consistently supported this association, and thus more research is needed to establish a clear and definitive link between talcum powder use and cancer. Despite this, recent molecular-level data have linked talc to alterations in redox balance, gene mutations, and inflammatory responses. Specifically, we have identified a role for talc to induce the pro-oxidant state, inhibit apoptosis, and more importantly induced cellular transformation in normal ovarian cells. EXPERT OPINION: We presented unequivocal evidence to support our opinion that talc is not biologically inert and induces molecular changes that mimic the hallmarks of cancer.

Exposure to cosmetic talc and mesothelioma.

AIM: Mesothelioma is associated with asbestos exposure. In this case series, we present 166 cases of individuals who had substantial asbestos exposure to cosmetic talc products as well as some who had potential or documented additional exposures to other asbestos-containing products and who subsequently developed mesothelioma. METHODS: Data were gathered for all subjects referred to an occupational and environmental medicine specialist as part of medicolegal review. Years of total cosmetic talcum powder usage was noted as well as the latency from the onset of talcum powder use to the mesothelioma diagnosis. Alternate asbestos exposure in addition to the exposure from cosmetic talc was categorized as none, possible, likely, and definite. RESULTS: In 122 cases, the only known exposure to asbestos was from cosmetic talc. For 44 cases, potential or documented alternate exposures in addition to the cosmetic talc were described. CONCLUSION: Cumulative exposure to asbestos leads to mesothelioma; for individuals with mixed exposures to asbestos, all exposures should be considered. Use of cosmetic talc is often overlooked as a source of asbestos exposure. All individuals with mesothelioma should have a comprehensive history of asbestos exposure, including cosmetic talc exposure.

Protective Effects of Zhi Ciweipi Water Extracts on Dextran Sulfate Sodium Salt⁃Induced Ulcerative Colitis in Mice / 中国生物化学与分子生物学报

Ulcerative colitis (UC) is a disease characterized by chronic inflammation of the intestinal mucosa. However, its exact pathogenesis is not fully understood. Zhi Ciweipi (ZCWP), as a traditional Chinese medicine (TCM), has demonstrated suitable anti-inflammatory effects in the treatment of patients with bloody stool and hemorrhoids. However, its therapeutic effects on ulcerative colitis have yet to be investigated in depth. The aim of this study was to investigate the protective effect of the aqueous extract of ZCWP against dextran sulfate sodium salt (DSS)-induced ulcerative colitis in mice and its possible mechanism of action. Successful simulation of ulcerative colitis was achieved by providing mice with drinking water containing 3% DSS. The HE staining results revealed that the aqueous extract of ZCWP could significantly reduce DSS-induced colonic injuries. Transcriptome sequencing analysis identified 10 key inflammation-related genes (IL⁃6, IL⁃1β, CSF2, TNF, IL10, IFN⁃γ, CXCL1, CXCL2, CXCL9, CXCL10), all of which were significantly downregulated (P<0. 05) in response to treatment with the aqueous extract of ZCWP according to qRT-PCR and Western blotting analyses. The immunofluorescence results further indicated that the aqueous extract of ZCWP was able to reduce the DSS-induced increase in the proportion of M1-type macrophages in the colon. Using single-cell sequencing, we thoroughly investigated the signaling relationships between different cell types, which revealed particularly strong communication between M1-type macrophages and fibroblasts. Subsequent qRT-PCR and Western blot analyses verified that the aqueous extract of ZCWP significantly downregulated the expression of DSS-induced fibrosis-related genes in colonic tissues (P<0. 05). In conclusion, the results of this study suggest that the aqueous extract of prepared ZCWP exerts a protective effect against DSS-induced ulcerative colitis by inhibiting M1-type macrophage polarization, downregulating the expression of inflammatory factors, and preventing strong communication between M1-type macrophages and fibroblasts. These findings not only reveal the therapeutic mechanism by which ZCWP aqueous extract treats colitis, but also provide a new theoretical basis for its application in clinical practice.

Association Between the Frequent Use of Perineal Talcum Powder Products and Ovarian Cancer: a Systematic Review and Meta-analysis.

BACKGROUND: Risk of ovarian cancer in women with frequent perineal talcum powder product is not well understood. Prior systematic reviews focused on ever use. The purpose of this study is to estimate the association between frequent (at least 2 times per week) perineal talcum powder use and ovarian cancer. METHODS: A systematic review and meta-analysis was conducted according to meta-analysis of observational studies in epidemiology guidelines. Study protocol was prospectively registered at PROSPERO (registration number CRD42020172720). Searches were performed in PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials databases from their inception to August 2, 2021. Case-control and cohort studies were included if they reported frequent perineal talcum powder use and an adjusted odds ratio or hazard ratio for ovarian cancer. Review for inclusion, data extraction, and quality assessment (using the Newcastle-Ottawa Scale [NOS]) were performed independently by two reviewers. Pooled adjusted odds ratios with 95% confidence intervals were generated from the random effects model. Heterogeneity was quantified with I2 statistic. Funnel plot and Eger's test were performed to assess publication bias. Subgroup and sensitivity analyses were performed for testing the robustness of the overall findings. RESULTS: Initial database searches returned 761 unique citations and after review, eleven studies describing 66,876 patients, and 6542 cancers were included (Cohen's κ = 0.88). Publication quality was high (median NOS = 8, range: 4 to 9). Frequent talcum powder use was associated with an elevated risk of ovarian cancer (adjusted pooled summary odds ratio 1.47 (95% CI 1.31, 1.65, P<0.0001). There was no evidence of bias and low heterogeneity (I2= 24%, P=0.22). There was no meaningful difference limiting analysis to publications with a NOS quality score of 8 or 9 or limiting studies based on study design. CONCLUSIONS: This review suggests an increased risk of ovarian cancer associated with frequent perineal powder exposure of 31-65%.

A novel model of constrictive pericarditis associated with myocardial fibrosis in rats.

An efficient animal model is fundamental for studies on the underlying mechanisms of constrictive pericarditis (CP). A novel CP rat model was established by pericardial injection composing of lipopolysaccharides (LPS) and talcum powder without thoracotomy. Pathological changes were confirmed by histological staining. E-flow Doppler of mitral valve, tissue Doppler E' in the medial mitral annular (E'sep ) and the lateral mitral annular (E'lat ) were measured to assess ventricular filling function. Circumferential, longitudinal, and radial strains (SC, SL and SR) and the respective strain rates (SrC, SrL and SrR) were analyzed in interventricular septum (IVS) and left ventricular free wall (LVFW). Rat cardiac fibroblasts (CFs) were treated with LPS. The activation of transforming growth factor ß1 (TGF-ß1) was confirmed by Q-PCR and western blot assays. Thickening of pericardium and fibrosis in pericardium and subepicardial myocardium were showed in the model group. Diastolic dysfunction in the CP group was indicated by decreased E'lat and E'lat /E'sep , increased E/E'lat , decreased EFW of SrC and SrL, increased AIVS and decreased E/A of SrC, SrL and SrR. Systolic dysfunction was indicated by decreased SCFW and SLFW in CP rats. The levels of TGF-ß1, p-Smad2/3, α-smooth muscle actin (α-SMA), and collagen-I/III (COL-I/III) were increased in the CP group. The increased TGF-ß1 that induced by LPS activated and phosphorylated Smad2/3 resulting in the secretion of α-SMA and COL-I/III. This model is of vital importance in studying the pathogenesis of CP.

Analytic comparison of talc in commercially available baby powder and in pelvic tissues resected from ovarian carcinoma patients.

OBJECTIVE: Measure the size and shape of talc particles in talcum powder and compare this data to the size and shape of talc particles found in surgically resected tissues from patients with ovarian carcinoma. METHODS: Using polarized light microscopy (PLM) and scanning electron microscopy (SEM), we measured the size and shape of talc particles in samples of talc-containing baby powder (TCBP) and surgically resected pelvic tissues (hysterectomies) from talc-exposed patients with ovarian carcinoma. RESULTS: The most frequent class of particles in TCBP can be unequivocally identified as talc, using both polarized light microscopy and scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDX). The talc particles found in resected tissues from ovarian carcinoma patients are similar in size and shape to the most abundant morphological class of particles in TCBP. CONCLUSIONS: This finding, combined with previous epidemiological literature and tissue-based analytical studies, provides further evidence that the small, isodiametric particles that dominate TCBP can migrate from the perineum and become lodged in distal structures in the female reproductive tract, where they may lead to an increased risk of developing ovarian carcinoma.

Talc exposure and risk of stomach cancer: Systematic review and meta-analysis of occupational cohort studies.

BACKGROUND/PURPOSE: Talc powder is widely used in various industries, but the carcinogenic effects associated with talc are not well understood. The objective of this study was to estimate the risk of stomach cancer after occupational talc exposure. METHODS: We conducted a meta-analysis was performed to calculate the meta-relative risk (mRR) of stomach cancer. We searched the MEDLINE, EMBASE, CNKI and Wanfang Data databases for publications prior to January 1, 2017 using talc, cancer, and mortality as the search terms. Only cohort studies with occupational talc exposure and stomach cancer statistics were included. RESULTS: All pooled analyses were based on random-effects models. We selected 13 observational studies (12 publications) for the meta-analysis, and heterogeneity was observed among studies. Workers exposed to all forms of talc had a significantly increased mRR of 1.21 (95% CI: 1.03-1.42, p = 0.02) for stomach cancer. Workers exposed to talc not containing asbestiform fibers also had an increased mRR of 1.26 (95% CI: 0.97-1.63, p = 0.09). CONCLUSION: The available data showed a positive association between occupational talc exposure and risk of stomach cancer. The association between talc not containing asbestiform fibers and risk of stomach cancer was not significant. Further epidemiological studies are required to evaluate the safety of talc.

Characterization of Airborne Particles Emitted During Application of Cosmetic Talc Products.

A pilot study was undertaken to characterize the concentration, duration and particle size distribution of the talc cloud that forms in the personal breathing zone (PBZ) during application of certain talc-containing cosmetics. Multiple direct-reading instruments were employed to simultaneously monitor PM4 concentrations (particulate matter with aerodynamic diameter < 4 µm; mg/m3) at different distances from each of three subjects while they applied talc products. Results indicated that the purpose and method of applying the talc product, combined with behavioral and physical differences amongst subjects, all strongly influenced airborne talc concentrations and the duration of the cloud. Air concentrations of talc in the PBZ averaged around 1.0 mg/m3, and the duration of exposure varied from less than one minute to more than ten minutes. The real-time monitors captured the occasional formation of secondary clouds, likely caused by resuspension of talc particles from skin or other surfaces. Measurements of aerosolized baby powder, face powder, and two adult body powders indicated that the median aerodynamic diameter of the talc cloud ranged from 1.7 to 2.0 µm. These direct-reading approaches were valuable for providing detailed characterization of short duration exposures to airborne talc particles, and will be useful to support future exposure assessments of talc and other powders in consumer products.

Diaper dermatitis: a survey of risk factors in Thai children aged under 24 months.

BACKGROUND: To identify the prevalence and risk factors associated with diaper dermatitis in Thai children aged 1-24 months. METHODS: This was a cross-sectional study of 1153 participants using structural questionnaires, which was conducted at Khon Kaen University Faculty of Medicine Pediatric department in Thailand. Univariate and multivariate logistic regression analyses were used to test the association between diaper dermatitis and its possible risk factors. RESULTS: The prevalence of diaper dermatitis among the study population was 36.1%, a rate which significantly decreased with age. The highest prevalence was found in subjects who were one to six months old. Risk factors that had a statistically significant association with diaper dermatitis in both univariate and multivariate analysis were i) diaper changing fewer than three times/night, ii) previous episodes of diaper rash, iii) using cloth diapers, and iv) topical application of baby talcum powder to the diaper area. CONCLUSIONS: Frequent diaper changings during the daytime do not compensate for fewer changings during the night. Moreover, the use of baby talcum powder on the diaper area significantly increased the risk of diaper dermatitis among the study population. These findings should be applied in future preventive strategies for diaper dermatitis in this age group.

Potential Airborne Asbestos Exposure and Risk Associated with the Historical Use of Cosmetic Talcum Powder Products.

Over time, concerns have been raised regarding the potential for human exposure and risk from asbestos in cosmetic-talc-containing consumer products. In 1985, the U.S. Food and Drug Administration (FDA) conducted a risk assessment evaluating the potential inhalation asbestos exposure associated with the cosmetic talc consumer use scenario of powdering an infant during diapering, and found that risks were below levels associated with background asbestos exposures and risk. However, given the scope and age of the FDA's assessment, it was unknown whether the agency's conclusions remained relevant to current risk assessment practices, talc application scenarios, and exposure data. This analysis updates the previous FDA assessment by incorporating the current published exposure literature associated with consumer use of talcum powder and using the current U.S. Environmental Protection Agency's (EPA) nonoccupational asbestos risk assessment approach to estimate potential cumulative asbestos exposure and risk for four use scenarios: (1) infant exposure during diapering; (2) adult exposure from infant diapering; (3) adult exposure from face powdering; and (4) adult exposure from body powdering. The estimated range of cumulative asbestos exposure potential for all scenarios (assuming an asbestos content of 0.1%) ranged from 0.0000021 to 0.0096 f/cc-yr and resulted in risk estimates that were within or below EPA's acceptable target risk levels. Consistent with the original FDA findings, exposure and corresponding health risk in this range were orders of magnitude below upper-bound estimates of cumulative asbestos exposure and risk at ambient levels, which have not been associated with increased incidence of asbestos-related disease.

Does Sericin, as a Novel Pleurodesis Agent, Have Higher Effectiveness Compared to Talcum Powder, Doxycycline, and Silver Nitrate Pleurodesis?

INTRODUCTION: The usefulness of sericin as pleurodesis agent has previously been described. Present study aims to compare sericin pleurodesis regarding success, effectiveness, tolerability, and side-effects. METHODS: Adult, 12-week-old Wistar-albino rats (n=60), divided to five groups as sericin, talcum-powder, doxycycline, silver-nitrate and control. Agents were administrated through left thoracotomy, rats sacrificed twelve-days after. RESULTS: Highest ratio of collagen fibers was observed in sericin group, and the intensity was higher than talcum-powder group (p<0.05). Compared to silver nitrate, sericin group displayed better mesothelial reaction, and multi-layer mesothelium was also better (p<0.05). Foreign body reaction and emphysema were less frequent in sericin group (p<0.05). The presence of biological tissue in parenchyma was less prominent in sericin group (p<0.05). Foreign body reaction on thoracic wall was less common in sericin group (p<0.05). Presence of biological tissue glue in thoracic wall was less prominent in sericin group (p<0.05). Glomerular degeneration was lower in sericin group compared to the silver nitrate group (p<0.05), and tubular degeneration was less common in sericin group than talcum group (p<0.05). Pericarditis was less common in sericin group compared to the other groups (p<0.05). CONCLUSION: As an intrinsic, natural glue protein, sericin protects the lung parenchyma and tissues, and its glue-like characteristics enable pleurodesis. The success of sericin in pleurodesis was demonstrated in the present study based on investigations of the pleurae. Being cost-effective and better tolerated agent associated with a low potential of side effects, sericin is more effective, less expensive and provides more lung parenchyma protection.

Evaluation of the presence of asbestos in cosmetic talcum products.

Talc has been used for over a century in a variety of cosmetic products. While pure cosmetic talc (free of asbestos) is not considered a risk factor for mesothelioma, it has been recently suggested that inhalation of cosmetic talc containing trace levels of asbestos is a risk factor for mesothelioma. Bulk analyses of cosmetic talcum products were performed in the 1960s and 1970s, however, the analytical methods used at that time were incapable of determining whether asbestos minerals were present in the asbestiform versus non-asbestiform habit. The distinction between these two mineral habits is critical, as non-asbestiform amphibole minerals do not present an asbestos-related cancer risk via inhalation. As such, we evaluated six historical talcum powders using modern-era analytical methods to determine if asbestos is present, and if so, to identify the mineral habit (asbestiform versus non-asbestiform) of the asbestos. Based on their labels, the products were produced by four manufacturers and sold between 1940 and 1977. The products were analyzed in duplicate by two laboratories using standard protocols. Laboratory A analyzed samples using X-ray diffraction (XRD) and polarized light microscopy (PLM), and Laboratory B analyzed samples using PLM and transmission electron microscopy (TEM) with energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED). No asbestiform minerals were found in any of the products. Nonetheless, even if some historical cosmetic talcum products contained trace amounts (≤0.1%) of asbestiform minerals, any resulting asbestos exposure would be expected to be exceedingly low, and comparable to exposures from breathing ambient air.

Methodological study on microbial limit test of zinc oxide and talcum powder lotion / 药物评价研究

Objective To establish a method for the microbial limit test of zinc oxide and talcum powder lotion in Chinese Pharmacopoeia 2015.Methods Microbial enumeration test and specified microorganisms test with instructions were conducted from Chinese Pharmacopoeia 2015,which involved 10 batches zinc oxide and talcum powder lotion and five species of bacteria in all.The samples were treated by centrifugation and membrane filtration.Microbial enumeration test:the total number of aerobic bacteria using TSA medium to examine,strains were Staphylococcus aureus,Pseudomonas aeruginosa,Bacillus subtilis,Candida albicans,and Aspergillus niger;The total number of molds and yeasts using SDA culture medium to examine,strains were Candida albicans and Aspergillus niger.Each strain was divided into two groups:Adding bacteria test group and bacteria control group.Samplecontrol group and negative control group of each culture medium was prepared respectively.Count the colonies and calculate the rate of recovery.Specified microorganisms test:Pseudomonas aeruginosa and Staphylococcus aureus were applicated and set the bacteria validation group,sample control group,and negative control group.The culture medium of each group was crossed on the corresponding medium plate,and Microflex LT mass spectrometer was used to identify the bacteria.Results The recoveries of all kinds of strains in microbial enumeration test,total yeast and mold count were 0.75-1.16 in all batches.In the validations of Staphylococcus aureus and Pseudomonas aeruginosa,all kinds of strains were respectively detected in bacteria validation group,and there were no bacterial growth in sample control group and negative control group.Conclusion The microbiological examination methods for zinc oxide and talcum powder lotion can meet the requirements of Chinese Pharmacopoeia 2015.

Assessment of Health Risk from Historical Use of Cosmetic Talcum Powder.

This study's objective is to assess the risk of asbestos-related disease being contracted by past users of cosmetic talcum powder.  To our knowledge, no risk assessment studies using exposure data from historical exposures or chamber simulations have been published. We conducted activity-based sampling with cosmetic talcum powder samples from five opened and previously used containers that are believed to have been first manufactured and sold in the 1960s and 1970s.  These samples had been subject to conflicting claims of asbestos content; samples with the highest claimed asbestos content were tested.  The tests were conducted in simulated-bathroom controlled chambers with volunteers who were talc users.  Air sampling filters were prepared by direct preparation techniques and analyzed by phase contrast microscopy (PCM), transmission electron microscopy (TEM) with energy-dispersive x-ray (EDX) spectra, and selective area diffraction (SAED).  TEM analysis for asbestos resulted in no confirmed asbestos fibers and only a single fiber classified as "ambiguous."  Hypothetical treatment of this fiber as if it were asbestos yields a risk of 9.6 × 10-7 (under one in one million) for a lifetime user of this cosmetic talcum powder.  The exposure levels associated with these results range from zero to levels far below those identified in the epidemiology literature as posing a risk for asbestos-related disease, and substantially below published historical environmental background levels.  The approaches used for this study have potential application to exposure evaluations of other talc or asbestos-containing materials and consumer products.

Study on the Optimization of Processing Technology of Dog Testes and Penis Processed with Talcum Pow-der and Its Quality Standard / 中国药房

OBJECTIVE:To screen the optimal technology of dog testes and penis processed with talcum powder,and to pro-vide reference for the formulation of quality control standard. METHODS:Taking the comprehensive score of crushing rate and the content of alcohol soluble extract as evaluation indexes,L9(34) orthogonal test was used to optimize processing temperature,pro-cessing time and the amount of talcum powder;validation test was conducted. According to related method in Chinese Pharmaco-poeia(2015 edition),the contents of moisture,ash,nitrogen and alcohol soluble extract were determined,and automatic amino ac-id analyzer was used to determine the content of amino acids in samples. RESULTS:The optimal processing technology were that 100 kg dog testes and penis should add into 40 kg talcum powder;the processing temperature was 350-380 ℃;processing lasted for 4 min. Results of verification test showed that the average crushing rate and the content of alcohol soluble extract were 80.2%(RSD=0.95%,n=3)and 15.7%(RSD=2.30%,n=3). In processed dog testes and penis,the contents of moisture,ash,nitro-gen and alcohol soluble extract were 5.7%,18.7%,8.3%,15.7%,respectively. Besides,there still were 16 kinds of amino ac-ids,and their total content was 42.44%. CONCLUSIONS:The optimized talcum powder processing technology of dog testes and penis is stable and practical. The content of moisture,ash,nitrogen,alcohol soluble extract and amino acid can be used as impor-tant quality standard control indexes for processed dog testes and penis.

Novel application method of talcum powder to prevent sticking tendency and modify release of esomeprazole magnesium enteric-coated pellets.

Actually, reflecting drug release from polymer-coated pellets remains a challenge. In this study, sticking of pellets caused by Eudragit®L30D-55 was observed during the release process, leading to change in drug release. Talcum powder (talc) was used in esomeprazole magnesium pellets to prevent sticking and modify release of pellets. Three methods including talc incorporated in enteric layer, physically mixed and coating resulted pellets were employed to prevent the sticking. The release of pellets was modified by addition talc into subcoat. The dispersion coefficient (Fd) and release profiles were determined in phosphate buffer solution (pH 6.8 and 6.0) and distilled water. It was found that the first manner made Fd increase to about 0.75, but the latter two methods could completely prevent sticking. Also, the second manner was more simple and readily scaled up. In addition, talc in subcoat significantly slowed the drug release in water, but the slowing release effect is less pronounced at pH 6.0 and 6.8. These different effects of talc were attributed to a different release mechanism in three media. The release profiles in water were fitted to Nuttanan model, and the K designated as "diffusive resistance constant" was linearly increased with talc levels in subcoat (R(2)=0.9874).

Application of talcum powder, trichloroacetic acid and silver nitrate in female rats for non-surgical sterilization: evaluation of the apoptotic pathway mRNA and miRNA genes.

There are several methods used for non-surgical sterilization in birth control including quinacrine, trichloroacetic acid (TCA), erythromycin, tetracycline, silver nitrate and talcum powder. Among these, talcum powder, TCA and silver nitrate are the most commonly used. However, the toxic and carcinogenic activities of these chemicals in ovarian tissue have been poorly elucidated. This study demonstrates the expression levels of antioxidant, apoptotic and anti-apoptotic genes after administration of talc powder, TCA and silver nitrate for non-surgical sterilization in female rat models. The expression changes of some microRNAs (miR-15b, miR-21, miR-34a and miR-98) that play key roles in the apoptosis pathway were also included. All expression analyses were evaluated with real-time PCR. The expression levels of all genes appeared to be upregulated in the talcum powder group, but the results were not statistically significant. Increased expression of Gsr and Sod1 genes was statistically significant in the talcum powder group. In TCA and silver nitrate group, expression of all genes was appeared to be elevated but only the Gsr expression was statistically significant in the TCA-administrated group; there were no statistically significant changes in the silver nitrate group. miRNA expression levels were increased in talcum powder and TCA-administrated groups, but these results were not significant. Expression levels of miR-15b, miR-21 and miR-98 in the silver nitrate group were significantly increased. Consequently, these chemicals appear to be non-carcinogenic agents for rat ovarian tissue which do not induce apoptosis. However, talcum powder and TCA can be considered as agents that are toxic to ovarian tissue.

Asbestos in commercial cosmetic talcum powder as a cause of mesothelioma in women.

BACKGROUND: Cosmetic talcum powder products have been used for decades. The inhalation of talc may cause lung fibrosis in the form of granulomatose nodules called talcosis. Exposure to talc has also been suggested as a causative factor in the development of ovarian carcinomas, gynecological tumors, and mesothelioma. PURPOSE: To investigate one historic brand of cosmetic talcum powder associated with mesothelioma in women. METHODS: Transmission electron microscope (TEM) formvar-coated grids were prepared with concentrations of one brand of talcum powder directly, on filters, from air collections on filters in glovebox and simulated bathroom exposures and human fiber burden analyses. The grids were analyzed on an analytic TEM using energy-dispersive spectrometer (EDS) and selected-area electron diffraction (SAED) to determine asbestos fiber number and type. RESULTS: This brand of talcum powder contained asbestos and the application of talcum powder released inhalable asbestos fibers. Lung and lymph node tissues removed at autopsy revealed pleural mesothelioma. Digestions of the tissues were found to contain anthophyllite and tremolite asbestos. DISCUSSION: Through many applications of this particular brand of talcum powder, the deceased inhaled asbestos fibers, which then accumulated in her lungs and likely caused or contributed to her mesothelioma as well as other women with the same scenario.